Issue
When creating a new bill using Internet Explorer (IE), user is unable to select a vendor nor see the vendor list when clicking the drop down arrow or typing in the letter associated with vendor name. Same goes for Payment Terms and GL Accounts.
Solution: This is not an issue with the Bill.com system but rather the user's internet browser settings In order to use the system as designed, please make sure you have your Active X controls enabled.
To resolve the issue, please do the following:

Go to Internet Explorer
Click Tools
Click Internet Options
Click Security tab
Select Internet 6
Click 'Custom Level'
Make sure the following are ENABLED and then refresh browser page:

ActiveX controls and plug-ins section run active x controls and plug-ins - enable
Script ActiveX controls marked safe for scripting - enable
Scripting section active scripting - enable
Scripting of java applets - enable